Linkage analyses are being conducted in several large pedigrees segregating dominant non-syndromic deafness. After excluding linkage to the known DFNA and DFNB loci in these large DFNA families, we have initiated genome-wide screens and have identified new DFN loci such as DFNA20, DFNA27, DFNA28 and DFNA236. The location of these three new DFNA genes is being refined prior to initiating positional cloning strategies to identify the genes responsible for the progressive hearing loss. Additional families with dominant, progressive hearing loss are being ascertained with the goal of mapping and cloning the responsible genes.